Conventionally, a biological specimen observation apparatus which carries out observation of the progress of growth of a cultivated biological specimen is known.
In an apparatus of this kind, a method using time lapse observation is generally employed as a method for acquiring observation images of a biological specimen, but the following techniques have been proposed in the prior art, for example.
Patent Document 1 describes technology which enables the start of operation of an automatic time lapse observation when it has been detected that there has been a change in a biological specimen which is an observation object, after which, if it is detected that change in the biological specimen has stopped, the operation of automatic time lapse observation is halted.    Patent Document 1: Japanese Patent Application Publication No. 2004-309719
However, in the case of a technique which is disclosed in Patent Document 1, an image for detecting change in a biological specimen and an image obtained by time lapse observation started after detection are set to the same magnification rate at all times, and therefore it is not possible to observe a region where the biological specimen has changed at a high magnification rate, and hence there is a problem in that the biological specimen cannot be observed accurately.